Thanks for the response. I've been playing around with the JVC and measuring brightness (see my post on it today). Turns out when you change Crosstalk Cancellation to +8 the image is bright enough for me after the glasses as my 2D target of 12fl (I sit very close to the screen).
However, because my screen doesn't maintain polarisation when the image is reflected back it's actually only half as bright as my 2D image.
I'm banking on DLP being as bright as my JVC in 2D, but with no flicker and cross talk. The poor blacks could kill it though. Although I do enjoy watching animations and documentaries, which the blacks are less important. With this type of content, especially IMAX documentaries the JVC does a really poor job so I use my LG OLED which is spectacular.
I was hoping someone could guide me on the Optoma 142x. It's a data projector at heart so it only has 3000 lumens for white, does that mess with the 3D picture? At how cheap it is, I'd love it to fit the bill and run a dual setup.